feat: improve adaptation of the extension for Chrome Web Store

[amerikan]

As of now the extension is using Manifest v2 which is no longer supported by Chrome Web Store.

In Firefox, v3 support is currently limited when it comes to background scripts. v3 requires service_worker for background script, however, it's currently not enabled in Firefox's v3 manifest yet (officially tracked here). :(

[amerikan]

The following changes seem to work. Some changes needed are specifically for Manifest v3, but other are changes needed specifically for Chrome compatibility. For example Chrome uses chrome namespace instead of browser namespace ( see https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/Build_a_cross_browser_extension#api_namespace and https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/Chrome_incompatibilities#javascript_apis).

Though Firefox uses browser namespace, the chrome namespace also works so going forward it might be better to use that to make it cross-browser, not sure if there are any downsides to it.

diff --git a/src/background.js b/src/background.js
index 24e09e2..e15b47b 100644
--- a/src/background.js
+++ b/src/background.js
@@ -1,5 +1,5 @@
 async function removeDuplicateTabs() {
-  const tabs = await browser.tabs.query({});
+  const tabs = await chrome.tabs.query({});
 
   const duplicateIds = [];
   const bins = {};
@@ -12,11 +12,11 @@ async function removeDuplicateTabs() {
     }
   });
 
-  await browser.tabs.remove(duplicateIds);
+  await chrome.tabs.remove(duplicateIds);
 }
 
 async function groupTabsByDomain() {
-  const tabs = await browser.tabs.query({});
+  const tabs = await chrome.tabs.query({});
 
   const domainGroups = {};
 
@@ -39,7 +39,7 @@ async function groupTabsByDomain() {
     });
   }
 
-  await browser.tabs.move(newTabPositionIds, {
+  await chrome.tabs.move(newTabPositionIds, {
     index: 0,
   });
 }
@@ -54,4 +54,4 @@ async function handleToolbarButtonClick() {
   }
 }
 
-browser.browserAction.onClicked.addListener(handleToolbarButtonClick);
+chrome.action.onClicked.addListener(handleToolbarButtonClick);
diff --git a/src/manifest.json b/src/manifest.json
index 3423155..9138ba9 100644
--- a/src/manifest.json
+++ b/src/manifest.json
@@ -1,5 +1,5 @@
 {
-    "manifest_version": 2,
+    "manifest_version": 3,
     "name": "Tabtastic",
     "version": "1.0.2",
     "description": "Adds a browser button to help you sort tabs by domain and date, and close duplicate tabs.",
@@ -13,10 +13,10 @@
     "permissions": [
         "tabs"
     ],
-    "browser_action": {
+    "action": {
       "default_icon": "icons/icon.svg"
     },
     "background": {
-        "scripts": ["background.js"]
+        "service_worker": "background.js"
     }
   }

[amerikan]

For chrome.* vs browser.* future consolidation see w3c/webextensions#113